Chemicals, used in electronic industries such as semiconductor manufacture, include those of liquid state such as sulfuric acid and hydrogen peroxide. The demand for low concentration of impurity particles contained in these chemicals as a quality thereof is becoming stronger in these years due to the trend of micropattern and higher density of integrated circuits. A conventional method for satisfying this demand is to remove the impurity particles from the chemicals by filtering the chemicals minutely. However, even if the chemicals for electronic industries are filtered minutely, in some cases the concentration of the impurity particles in the chemicals at the place of use increases after they are infused into containers and transported to the place of use, and it is regarded as caused by the particles existing in the interior of containers.
The interior of the container is, of course, cleaned before infusing the chemicals into the same. Water-jet method using a rotary nozzle head is employed conventionally for cleaning the interior of the container. The rotary nozzle head with numerous cleaning liquid injection holes is rotatably attached to an end of a comparatively rigid pipe and rotated by the pressure of the cleaning liquid, typically ultra-pure water, introduced from the other end of the pipe. Therefore, an efficient cleaning is carried out since the injected ultra-water strikes against the entire inner surface of the container as moving a rotary nozzle head inserted into the container reciprocally between the opening portion and the bottom portion of the container while the ultra-pure water is injected from the injection holes of the rotary nozzle head. However, there is a fact that a very small amount of the particles still remain in the container even if the cleaning with ultra-pure water using the rotary nozzle head is carried out for a long time.